The subject invention relates to photography and, more particularly, to a three-dimensional effect representation and camera.
An observer is able to judge limited distances because of the slightly different aspect or view that each human eye receives of the scene, parallax. The views received by the eyes are combined by the brain to provide a three-dimensional view, where depth is perceived. In ordinary representations (transparencies, photographs, film . . . ) where the scene is recorded from a single direction, this depth is lost, the scene appears flat, two dimensional.
Over the years there have been numerous attempts to devise a three-dimensional effect using a two-dimensional photograph or transparency by dividing each representation into narrow vertical strips and interlacing them in one picture. A vertical grid in front of the picture is in precise registration with vertical strips to allow each eye to see the different strips to give a stereoscopic image. Such attempts have met with varying degrees of technical and commercial success. The mind of the observer wants to see in three dimensions and if given the opportunity, the mind will interpret visual information so as to cause the three-dimensional effect. The two-dimensional representations for providing the three-dimensional effect include numerous optical pairings, that is, visual pairings that can be seen concurrently by the observer's eyes. If one of these pairings is a stereoscopic pairing (a pairing that shows slightly different aspects of the same object) the mind will accept the stereoscopic pairing and ignore the non-stereoscopic optical pairings to obtain the three-dimensional effect. However, if a stereoscopic pairing is unavailable to the eyes when the two-dimensional representation is viewed from a particular angle, the representation will appear garbled and only two-dimensional.
In one early attempt to obtain a three-dimensional effect representation using a single lens incorporating a horizontal slit aperture, a line screen was located between the camera lens and the photosensitive film. The representation formed proved to be abnormal in that as the observer moved slightly laterally, the object photographed appeared to be moving longitudinally, that is, toward and away from the observer. For further information regarding this type of representation and the apparatus used in recording it, reference may be made to U.S. Pat. No. 1,882,424.
Photographic representations made and viewed under lenticular screens have been proposed and commercialized. The use of the lenticular screen is advantageous because it functions to divide the object field into lineform images and lenticules over the representation provided stereoscopic pairings. One of the many problems associated with the use of lenticular screens when used directly is that the object appears reversed and additional lenticular lenses or prisms are required to reverse the line form images to obtain normalcy. Another problem is that the use of the lenticular screen makes it difficult to fill the entire area of the photosensitive material under the screen. Under normal circumstances, the area under each lenticule will include comparatively large portions which are not exposed. At certain viewing distances or angles, the observer would see two unexposed areas through lenticules of the viewing screen, thus ruining the three-dimensional effect. For further information regarding optical components for image reversal and a method and apparatus for completely filling the photosensitive material under the lenticules, reference may be made to U.S. Pat. Nos. 3,535,993 and 3,895,867, respectively.